Process for treating casein.



A. BARTELS.

PROCESS FOR TREATING CASEIN. APPLICATION FILED DEC.28,I915- RENEWED Aus. 16, 1916.

Patented Dec. 19, 1916.

v To all whom it mag concern:

PROCESS FOR TREATING CASEIN.

encased.

Specification of Letters Patent.

Application filed- December 28, 1915, Serial No. 69,104. Renewed August 16, 1916. Serial Ito. 115,33t.

Be it known that I, Dr. Amazons BAR; TELS, a subject of the King of Prussia, re-

siding at Buxtehuderstrasse 102, Harburg on-the-Elbe, in the Kingdom of Prussia, German Empire, have invented certain new and useful Improvements in Processes for Treating Casein, of which the following is a specification.

It hasalready been proposed to produce transparent horn-like casein masses by first dissolving the casein in caustic alkali, then allowing the solution to settle in order to free it from the particles contained in suspension therein, and then obtaining the casein by precipitation from the resulting clear solutlon. Although that method is suitable for the production oftransparent horn-like masses, yet as the casein is decomposed by the treatment with alkali and consequently loses partly its original properties, in working up the casein to form plastic masses, various drawbacks have been experienced which have not been remedied hitherto. Further, that process entails a great loss of casein. It has hitherto not been possible to produce vremuneratively on a large scale such transparent hornlike masses from undecomposed casein.-

T have now discovered that undecomposed casein will produce useful and completely transparent casein masses if the casein is first treated in a suitable manner with fat solvents. The selection of such solvents as well as the manner of treating the casein with them, is of extreme importance.-

The improved process according to the present invention, now consists in treating dry commercial casein for a considerable time with energetic stirring with an extracting agent while heating and treating the product in theusual manner after drying;

' It has already been proposed to deprive casein of its fat by means of fat solvents; it

has however been found that a complete deprivation of fat encounters great difliculties. It has been proposed to employ for instance, ether-alcohol as an agent for depriving casein of its fat. On account of the low boiling point of ether however, ether-alcohol can only be employed'at ordinary temperatures for removing fat, and in such a case no casein 1s produced wh1ch ylelds a trans-, What is known as parent horn-like mass. chemically pure casein which has been deprived of its'fat according to this etheralcohol process and which 1s placed on the transparent casein masses on a commercial scale from undecomposed casem has until the advent of the present lnventi'on remained unsolved. The applicant has discovered that mixtures of alcohol and benzin or alcohol and benzol are especially suitable for use in efi'ecting a proper preparation of the casein, without changing the quality of the latter.. There are of coursea large number of other fat-removing agents but their use has always been accompanied with some drawbacks,- either because the quality of the casein was deteriorated thereby or because the extracting agent did not penetrate suificiently deeply into the casein.

The alcohol mixtures of benzin or benzol may be heated to a higher degree than an ether-alcohol mixture without evaporatin and as the time required for treatment 0 the casein is thus considerably diminished, as compared to ether treatment which is operated at normal temperatures, any deleterious efi'ect on the casein due to prolonged treatment is avoided and larger quantities of casein of a better quality are thus produced. The use of ether furthermore, as a solvent, results in the total extraction of fat a small quantity at least of fat should remain'in the casein, otherwise the casein will notlend itself readily to processes of compression or the like when converting the casein intohorny masses for the purpose of making various articles. Y

In carrying the improved process into practice, it is first ascertained by means of 'tests how long the treatment of. the particular casein with the alcohol mixture must be continued. After having thus ascertained the minimum time for the determined operation, which may under certain circumstances be six hours andsometimes longer, the treatment of the casein is then carried into efiect accordingly. The casein is mixed in an extracting vessel in which the mixture is kept 1 pletion of the operation. The separated extracting liquidis used after distillation for treating further quantities of casein..

The mixtures of alcohol with benzol or benzin have in this process the particular advantage that the constituents pass over together in the distillation, and the distillate can be used again directly for the same purpose. After having been sufiiciently treated with the extracting agent, the casein still moist with the latter, is dried by means of heat and vacuum.

As regards plastic properties, elasticity and workability by tools, the transparent horny mass produced from the casein that has undergone the described preliminary treatment, has exactly the same properties as the mass made from the corresponding commercial casein.

T have further discovered, especially in treating large quantities of casein, that the process can be considerably improved by agitating dry commercial casein with the solvent in a rotating extracting vessel, said solvent being renewed if necessary, whereupon after the discharge of the extracting agent, the casein is heated in the rotating vessel with energetic movement in a vacuum for the purpose of drying'and is then treated further in the usual manner to produce artificial masses. This process not only considerably diminishes the requisite duration of the treatment, but it also permits the production of a useful transparentcasein mass on a commercial scale by the use of strong alcohol alone.

The success of the above described process is no doubt due above all to the fact that each grain of casein is treated as uniformly as possible and as thoroughly as possible with the extracting agent. Namely, all the grains, even those which resist most to the action of the extracting agent, are treated as thoroughly as possible. A rotatable movement of the vessel for containing the mixture of casein and extracting agent is most desired as. any other kind of movement of the vessel for agitating the casein with the extracting agents certainly renders this uniform action of the extracting agent upon each grain of casein much more difficult, perhaps prevents it altogether. Even a few traces of left-over constituents are suflicient to afiect the result unfavorably.

A suitable construction of the apparatus,

for carrying out the improved process of this invention is illustrated by way of example in the accompanying drawings in which Figure 1 is a cross section and Fig. 2 is a longitudinal section of the apparatus.

The strainer drum a is mounted to rotate in ball bearin s b in the lower half 0 of the liquid-containing cylinder. The upper part (i of the cylinder is constructed as a remov- 1 able cover and allows of effecting a tight closure. The lower part 0 of the cylinder is provided with a heating jacket e which, if.

aoaese The solvent liquid is supplied at f and asses out at g. The strainer drum is provi ed on its periphery with scooping channels it and.

-into the jacket e according to requirement.

By reasonof theopen-topped construction of the mounting and the division of the drum shaft, the strainer drum a can be removed after opening the cylinder cover d. The connection of the parts of the divided shaft is eflected by means of a suitable coupling. For the purpose of enabling the drum when removed to be rapidly filled and emptied, one. end wall of the same is made wholly or partly removable. This arrangement also allows in an extremely simple manner, of utilizing the apparatus as an apparatus for drying the material to be treated, for which purpose drying air is passed through the cylinder and the strainer drum instead of the liquid solvent.

It may be observed for instance that the temperature of the mixture in the extracting vessel may be at 8090 centigrade. The vessel is practically filled to Q; or -l;.

I claim:

1. A process for treating casein for the purpose specified which consists in heating and agitating a mixture including casein,

ing and heating a mixture of casein, alcohol and benzol.

4. A process for treating casein for the purpose specifiedv which consists in agitating and heating casein with an alcoholic fat extracting mixture containing 'benzol.

5. A process for treating casein for the purpose specified which consists in first heating the casein with an alcoholic fat extracting mixture containing benzol in a quickly revolving vessel which is heated to 80 or 90 degrees centigrade, drawing ofi the extracting agent, and finally drymg the casein while still within the rotating vessel.

6. A process for treating casein for the purpose specified which consists in extracting nearly all of the fat therefrom by means Laoaese I Q of a relatively weak fatextracting mixture and agitating casein with an organic liquid in the presence of heat. reagent containing a relatively Weak fat-ex- 7. A process for treating casein for the tractive. purpose specified which consists in extract- In testimony whereof I afix my signature 5 ing nearly all of the fat therefrom by means in presence of two witnesses.

of an alcoholic fat extracting mixture containing benzol in the presence of heat and AMANDUS R constant agitation. Witnesses:

8. A process for treating casein for the FRANCIS R. STEWART,

10 purpose described which comprises heating LoUIs F. DILGER. 

